• Konstantin (19/19) Oct 08 2014 Hello D-World,
• AsmMan (2/7) Oct 08 2014 Are you looking for parallel?
• Konstantin (7/9) Oct 09 2014 I have seen this, but I'm not sure how to use it.
• Sag Academy (2/11) Oct 09 2014 Yeah, it is.
• Russel Winder via Digitalmars-d-learn (22/39) Nov 02 2014 Or maybe not. The code above is fine per se, but only tackles the
• =?UTF-8?B?QWxpIMOHZWhyZWxp?= (7/10) Oct 09 2014 I have the following chapter with some examples:

"Konstantin" <konstantin_kraus t-online.de> writes:

Hello D-World,

I've written a small terraingenerator in D based on the 
Hill-Algorithm.

To generate a terrain I only need to call the method 
generateTerrain(...) which returns a float-Array containing the 
height of each pixel (2D Array mapped with a 1D array with length 
resolution^2).

What I'd like to do:
Generate #treads seperate maps in a own thread and combine and 
normalize them afterwards.

I have little to no experience working with multiple threads. I 
tried it once in java for University but did not really get 
working.

What I imagine as solution (I know it won't work this way, but to 
give you a better idea):

for(int i = 0; i < #threads; i++){
     runInThread(generateTerrain(...));
}

Greetings and thanks in advance Konstantin

"AsmMan" <jckj33 gmail.com> writes:

 What I imagine as solution (I know it won't work this way, but 
 to give you a better idea):

 for(int i = 0; i < #threads; i++){
     runInThread(generateTerrain(...));
 }

Are you looking for parallel? 
http://dlang.org/library/std/parallelism/parallel.html

"Konstantin" <konstantin_kraus t-online.de> writes:

 Are you looking for parallel? 
 http://dlang.org/library/std/parallelism/parallel.html

I have seen this, but I'm not sure how to use it.

Maybe:

float[][] maps = new float[#threads][resolution * resolution];

foreach(i, ref elem; parallel(maps)){
     elem = generateTerrain(...);
}

Does this look right?

"Sag Academy" <sagacademyjaipur gmail.com> writes:

On Thursday, 9 October 2014 at 10:10:20 UTC, Konstantin wrote:
 Are you looking for parallel? 
 http://dlang.org/library/std/parallelism/parallel.html

 I have seen this, but I'm not sure how to use it.

 Maybe:

 float[][] maps = new float[#threads][resolution * resolution];

 foreach(i, ref elem; parallel(maps)){
     elem = generateTerrain(...);
 }

 Does this look right?

Yeah, it is.

Russel Winder via Digitalmars-d-learn <digitalmars-d-learn puremagic.com> writes:

On Thu, 2014-10-09 at 11:29 +0000, Sag Academy via Digitalmars-d-learn
wrote:
 On Thursday, 9 October 2014 at 10:10:20 UTC, Konstantin wrote:
 Are you looking for parallel?=20
 http://dlang.org/library/std/parallelism/parallel.html

 I have seen this, but I'm not sure how to use it.

 Maybe:

 float[][] maps =3D new float[#threads][resolution * resolution];

 foreach(i, ref elem; parallel(maps)){
     elem =3D generateTerrain(...);
 }

 Does this look right?

=20
 Yeah, it is.

Or maybe not. The code above is fine per se, but only tackles the
generation phase, there will be later phases. It may be that other parts
of http://dlang.org/library/std/parallelism.html used slightly
differently would be better for describing more of the problem. taskPool
has a lot of interesting capabilities, including parallel reduce which
gives a full map=E2=80=93reduce type scatter=E2=80=93gather approach: OP di=
d mention
that there was a generation then integration activity overall.

Of course, if absolute performance is required things get a bit more
tricky avoiding overheads.

--=20
Russel.
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D
Dr Russel Winder      t: +44 20 7585 2200   voip: sip:russel.winder ekiga.n=
et
41 Buckmaster Road    m: +44 7770 465 077   xmpp: russel winder.org.uk
London SW11 1EN, UK   w: www.russel.org.uk  skype: russel_winder

=?UTF-8?B?QWxpIMOHZWhyZWxp?= <acehreli yahoo.com> writes:

On 10/09/2014 03:10 AM, Konstantin wrote:
 Are you looking for parallel?
 http://dlang.org/library/std/parallelism/parallel.html

 I have seen this, but I'm not sure how to use it.

I have the following chapter with some examples:

   http://ddili.org/ders/d.en/parallelism.html

If concurrency is more suited to your application, then there is the 
following as well:

   http://ddili.org/ders/d.en/concurrency.html

Ali